Design of symmetrical polylithic crystal filters

For the original article see ibid., vol.12, no.25, p203-3 (1976). C.C. Lin Provided an algorithm for designing symmetrical even-order all-pole bandpass polylithic crystal filters using dual-resonator monolithic crystal filter (MCF) elements. The commenter points out a couple of omissions in the algorithm given. With the corrections suggested, it was verified that the algorithm did provide a design procedure for all-pole filters that have any number of symmetrical MCF elements.